Can you add an Orange Widget that will allow to change the type of an attribute. When I open a file with Orange, it automaticlly detects it's attributes and their type, I want to be able to manually change the type.

There are widgets Discretize and Continuize, but they convert all of your attributes.

(I tried cirumventing this using "Select Attributes" to make one attribute a meta attributes, with the plan to move it back to a normal attribute after discretization. But my attempt failed since Discretize seems to discard metadata.)

We first create a new attribute. The second line tells that a2 is computed by taking the third attribute (of example ex), converting it into a string and then to float. Then we create a new domain and rewrite the existing table. (If the table is large, this gives you two large tables in the memory at once.)